I recently found a game (well a flash game) called One Chance, and the name says it all. You play as a scientist (though you don't really get the feel for being one) and you find the cure for cancer. Next day, after it has been created, you find out that it kills all cells, and is spreading through the world. It is estimated hat all cells on earth will die within 3 days. The game is you deciding what to do at work and with your family for the next 3 days. I liked it, and I think its worth checking out if you have nothing to do. I hope you enjoy!